Exhaust gas recirculation
blueEGR
Up to IMO Tier III. With water only.
blueEGR cuts the NOx emissions of existing diesel engines by up to about 80 %. It sits on top of the engine, needs no urea and no dry dock. For ships and power plants from 500 kW.
The numbers
What blueEGR delivers
Measured on installed systems. Values depend on the engine, the ship and the operating profile.
about 80 %
NOx reduction on MS Artania, from IMO Tier II to Tier III
78 %
NOx reduction on a RoRo ferry, from IMO Tier 0+ to Tier II
1 to 2 weeks
total conversion time in our 1,000 TEU case study
from 500 kW
engine power we build a system for
Only technical water
No urea, no chemicals, no ammonia slip and no compressed air supply.
No backpressure increase
The system does not raise fuel consumption by itself.
No loss of space
No funnel extension, no cabins lost. The unit sits on the exhaust pipe.
Is it right for you?
Who it is for and what you need
Made for
Ship owners and operators of cruise liners, ferries, container feeders, tankers and other ships with diesel engines.
Power plants with stationary diesel engines that have to meet stricter NOx limits.
Ships in emission control areas that need IMO Tier III, or a better Tier level for EEXI and CII.
Projects in Norway. blueEGR is a listed technology at the Norwegian NOx Fund.
What you need
A diesel engine from 500 kW. Marine or stationary. We check your engine type first.
Space on top of the engine. The system is mounted on the exhaust pipe above the engine.
Technical water. Supply from the fresh water system and a connection to waste water treatment. Not needed for the small system, which cools with a heat exchanger only.
Your engine data. Engine type, power at MCR, current and target IMO Tier level.
A few hours of engine time. That is all the engine is needed to connect the system.
Why now
Most ships have to act
Since 2023 the IMO requires an energy efficiency index for existing ships (EEXI) and a yearly carbon intensity rating (CII). For older ships, blueEGR plus the Fuel Saving Option is a retrofit route from IMO Tier 0+ to Tier II.
53 % above the EEXI limit
Container EEDI values from 2019 MRV data plotted against the EEXI limit. More than half of the fleet sampled does not comply without a technical measure.
Source: Lloyd’s Register webinar, March 2021
90 to 95 % have to adapt by 2030
A sample of 1,831 container ships from EU MRV data for 2019. Depending on the reduction scenario, nine out of ten need a measure to keep a CII rating of C or above by 2030.
Source: EU MRV data, 2019
How it works
Cooler combustion, less NOx
On top of the engine. The system is installed on the exhaust pipe and does not get in the way of engine maintenance.
Controlled by load. Part of the exhaust gas is taken off, depending on engine load.
Cooled and cleaned. Water cools and cleans the gas in the spray and demister housing.
Always monitored. A continuous emission monitoring system (CEMS) measures the result.
Back into the engine. The gas returns to the scavenging air. Combustion runs cooler and much less NOx is formed.
Working principle: exhaust gas is taken off, cooled and led back to the scavenging air.
Exhaust gas cycle: from the engine through spray housing, demister housing and an optional heat exchanger back to the turbocharger.
Three sizes
Sized for your engine
Every system is designed for your current and your target IMO Tier level and for the engine power at MCR.
| System | Engine power | Exhaust gas cooling | NOx target |
|---|---|---|---|
| blueEGR small | 500 kW to 1.5 MW | Heat exchanger only, no water | IMO Tier I to II |
| blueEGR light | 500 kW to 1.5 MW | Water cooling with injection nozzles | IMO Tier I to III |
| blueEGR full | from 1.5 MW | Water cooling with more injection nozzles | up to IMO Tier III |
Fuel Saving Option (FSO). In special cases, from IMO Tier 0+ to Tier II, the fuel injection timing can be set back. On a RoRo ferry this saved about 11 % fuel, with 11 % less CO₂ and particles.
Water cycle
Only technical water, in a closed loop
blueEGR needs no urea, no ammonia and no compressed air. Supply pumps bring cold water through a fine filter to the system. The hot water flows back through a drain tank, its pH value is checked and the water is cleaned in an oily water separator before it returns through the heat exchanger.
Supply and return water cycle, closed loop example.
How we work
From first check to certified engine
1 · Pre-study
We check your engine and your target Tier level.
2 · Design
The system is sized for your engine.
3 · Install
In port. The engine is needed for only a few hours to connect the system.
4 · Certify
We support you with class and the new certificate.
Real-world proof
Tested at sea
Before
After: blueEGR installed on top of the engine
Reference
MS Artania
The world’s first cruise liner upgraded to IMO Tier III with exhaust gas recirculation.
Cruise liner built in 1984 for 1,200 passengers, operated by Phoenix Reisen since 2011. Four Wärtsilä 12V32E main engines of 7 MW each, built to IMO Tier II.
1 · The task
From mid-2024 the ship needed IMO Tier III to keep sailing in sensitive areas such as the Norwegian fjords.
2 · How we solved it
In November 2022 blueEGR was installed directly on top of all four engines, without an SCR catalyst in the funnel. AES managed the project together with the ship’s technical managers.
3 · The result
In the final test in November 2023 NOx fell by about 80 %. In July 2024 Lloyd’s Register issued a new EIAPP certificate. The project was supported by the Norwegian NOx Fund.
Below the Tier III limit
IMO Tier II limit: 9.6 g/kWh at 750 rpm
Engine before: 8.2 g/kWh, measured by the engine maker
IMO Tier III limit: 2.4 g/kWh
Achieved with blueEGR: 2.0 g/kWh
about 80 %
less NOx
2.0 g/kWh
Tier III limit: 2.4 g/kWh
about 500 t
less NOx per year
IMO Tier III
certified July 2024
4 × 7 MW
Wärtsilä 12V32E engines
DNV class approval in principle, in line with the DNV rules for reciprocating internal combustion engines · Listed supplier for NOx reducing technologies at the Norwegian NOx Fund
Case study
Three routes to Tier III compared
A standard 1,000 TEU container feeder of the SSW Super 1000 type, about 13,000 dwt, with one main engine of about 9 MW, from IMO Tier II to Tier III.
| 1,000 TEU container feeder | Dual-fuel conversion | SCR catalyst | blueEGR with FSO | blueEGR without FSO |
|---|---|---|---|---|
| Engine update | 2,600,000 € | 50,000 € | 960,000 € | 915,000 € |
| LNG fuel gas and tank 500 m³ | 2,400,000 € | not needed | not needed | not needed |
| SCR catalyst, mixing unit, compressed air | not needed | 350,000 € | not needed | not needed |
| Shipyard | 4,550,000 € | 1,020,000 € | 160,000 € | 95,000 € |
| Project management | 30,000 € | 15,000 € | 5,000 € | 5,000 € |
| Sea trial | 75,000 € | 40,000 € | 20,000 € | 10,000 € |
| Off-hire at 10,000 € per day | 560,000 € | 280,000 € | 140,000 € | 70,000 € |
| Total cost | 10,215,000 € | 1,755,000 € | 1,285,000 € | 1,095,000 € |
| Total time | 8 weeks | 4 weeks | 2 weeks | 1 week |
Values and time frames are estimated and depend on shipyard, location and engine availability. Running costs are lowest with blueEGR, because only water is used.
Questions we hear
Your questions, answered
Do I need a dry dock?
No. The system is installed in port, and the engine is needed for only a few hours to connect it.
Does it need urea or chemicals?
No. It uses technical water only, so there is no urea, no ammonia slip and no compressed air.
Does it raise fuel consumption?
No. There is no increase in backpressure, so fuel consumption does not rise. With the Fuel Saving Option it can even fall.
Do I lose space on board?
No funnel extension is needed. The system sits on top of the engine, so no space for cabins or cargo is lost.
What about class and certificates?
DNV has issued a class approval in principle. We support you with the class society, as for MS Artania, where Lloyd’s Register issued a new EIAPP certificate.
Can I combine it with HYDRAULICA?
Yes. blueEGR and HYDRAULICA can be installed together.
Contact
Talk to us about your emissions
Send us your engine type, your current Tier level and the size of your ship or plant. We check what is possible and what it would cost.
All data on this page is non-binding and from individual projects. Every project is assessed individually.
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